Reuters: A granddaughter of Sumner Redstone wants to join Redstone’s ex-girlfriend in a lawsuit challenging Redstone’s mental competency, court filings show, an indication the media mogul’s family is not united in its view of his condition. Keryn Redstone, in a declaration filed in Los Angeles Superior Court, said her grandfather became a “prisoner in his own home” after the former girlfriend, Manuela Herzer, was ejected from his mansion last October.